US4341723A - Variable venturi carburetor - Google Patents

Variable venturi carburetor Download PDF

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Publication number
US4341723A
US4341723A US06/219,524 US21952480A US4341723A US 4341723 A US4341723 A US 4341723A US 21952480 A US21952480 A US 21952480A US 4341723 A US4341723 A US 4341723A
Authority
US
United States
Prior art keywords
fuel
main
bypass
venturi
main jet
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Expired - Fee Related
Application number
US06/219,524
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English (en)
Inventor
Hidenori Hirosawa
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Aisan Industry Co Ltd
Original Assignee
Aisan Industry Co Ltd
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Aisan Industry Co Ltd filed Critical Aisan Industry Co Ltd
Assigned to AISAN KOGYO KABUSHIKI KAISHA reassignment AISAN KOGYO KABUSHIKI KAISHA ASSIGNMENT OF ASSIGNORS INTEREST. Assignors: HIROSAWA HIDENORI
Application granted granted Critical
Publication of US4341723A publication Critical patent/US4341723A/en
Anticipated expiration legal-status Critical
Expired - Fee Related legal-status Critical Current

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Classifications

    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
    • F02M—SUPPLYING COMBUSTION ENGINES IN GENERAL WITH COMBUSTIBLE MIXTURES OR CONSTITUENTS THEREOF
    • F02M7/00—Carburettors with means for influencing, e.g. enriching or keeping constant, fuel/air ratio of charge under varying conditions
    • F02M7/12—Other installations, with moving parts, for influencing fuel/air ratio, e.g. having valves
    • F02M7/14—Other installations, with moving parts, for influencing fuel/air ratio, e.g. having valves with means for controlling cross-sectional area of fuel spray nozzle
    • F02M7/16—Other installations, with moving parts, for influencing fuel/air ratio, e.g. having valves with means for controlling cross-sectional area of fuel spray nozzle operated automatically, e.g. dependent on exhaust-gas analysis
    • F02M7/17—Other installations, with moving parts, for influencing fuel/air ratio, e.g. having valves with means for controlling cross-sectional area of fuel spray nozzle operated automatically, e.g. dependent on exhaust-gas analysis by a pneumatically adjustable piston-like element, e.g. constant depression carburettors
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
    • F02M—SUPPLYING COMBUSTION ENGINES IN GENERAL WITH COMBUSTIBLE MIXTURES OR CONSTITUENTS THEREOF
    • F02M3/00—Idling devices for carburettors
    • F02M3/08—Other details of idling devices
    • F02M3/09—Valves responsive to engine conditions, e.g. manifold vacuum
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
    • F02M—SUPPLYING COMBUSTION ENGINES IN GENERAL WITH COMBUSTIBLE MIXTURES OR CONSTITUENTS THEREOF
    • F02M3/00—Idling devices for carburettors
    • F02M3/08—Other details of idling devices
    • F02M3/12—Passageway systems
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
    • F02M—SUPPLYING COMBUSTION ENGINES IN GENERAL WITH COMBUSTIBLE MIXTURES OR CONSTITUENTS THEREOF
    • F02M7/00—Carburettors with means for influencing, e.g. enriching or keeping constant, fuel/air ratio of charge under varying conditions
    • F02M7/23—Fuel aerating devices
    • F02M7/24—Controlling flow of aerating air
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
    • Y10S—TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y10S123/00—Internal-combustion engines
    • Y10S123/11—Antidieseling
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
    • Y10S—TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y10S261/00—Gas and liquid contact apparatus
    • Y10S261/74—Valve actuation; electrical

Definitions

  • the present invention relates to a variable venturi carburetor for an internal combustion engine (hereinafter referred to as "engine") in which constant negative pressure in a venturi portion is utilized for controlling its air-fuel ratio.
  • a fuel bypass provided in a float chamber detours a main fuel metering portion to communicate with a downstream portion of a throttle valve. Therefore, the flow of fuel flowing in the fuel bypass is widely changed in proportion to change in engine load such that the air-fuel ratio cannot be maintained constant with respect to the change in engine load.
  • a fuel bypass detouring a main fuel metering portion for supplying part of the fuel to a venturi portion. Since the flow of the fuel supplied to the venturi portion through the fuel bypass is small in comparison with that of the main fuel when the engine is driven under load, the air-fuel ratio can be maintained constant regardless of change in engine load. When the engine is idly driven the air-fuel ratio can be also maintained constant, because the pressure of the venturi portion and the area of the bypass are constant respectively. In addition, the ratio of the flow of the bypass fuel and that of the main fuel becomes large so that the air-fuel ratio can be controlled by changing the flow of the bypass fuel. Further, the fuel bypass is provided with an electromagnetic valve for intercepting an outlet communicating with the venturi portion to effectively prevent the engine from dieseling that might be caused by stoppage of the engine.
  • FIG. 1 is a longitudinal cross sectional view of a first embodiment of the present invention
  • FIG. 2 is a longitudinal cross sectional view of a principal part of a second embodiment of the present invention.
  • FIG. 3 is a longitudinal cross sectional view of a principal part of a third embodiment of the present invention.
  • a variable venturi carburetor 1 has a venturi portion 6 which comprises a throttle valve 2, a suction piston 3 and a plate 15.
  • a suction chamber 5 comprises a cylinder provided in the carburetor 1 and the suction piston 3 which is slidable in contact with the inner wall surface of the cylinder.
  • the suction chamber 5 contains therewithin a coiled spring 3a which presses the suction piston 3 against the plate 15.
  • a negative pressure passage 4 which makes the suction chamber 5 communicate with the venturi portion 6.
  • a chamber 5a for intake air is defined between the rear surface of the slidable flange of the suction piston 3 and the body of the carburetor 1, into which air is introduced through an air passage 4a formed in the vicinity of the inlet of an air horn 20.
  • a metering needle 7 is mounted to the central portion of the bottom of the suction piston 3 facing the venturi portion 6, and the free end thereof is inserted into the interior of a main jet 8 which is provided in the middle portion of a main fuel passage 14 formed in the upper portion of a float chamber 18.
  • a portion 14a of the main fuel passage 14 upstream of the main jet 8 communicates with an inlet 9a of a fuel bypass 9, which detours the main jet 8 and has an outlet 16 communicating with another portion 14b of the main fuel passage 14 downstream of the main jet 8.
  • a bypass jet 11 Within the inlet 9a of the fuel bypass 9, there is provided a bypass jet 11, and a throttle 17 is provided within the outlet 16.
  • the outlet 16 is further provided with an electromagnetic valve 19 for closing the throttle 17.
  • An adjust screw 10 is provided for controlling the amount of throttling of the air throttle 12.
  • FIG. 2 shows a second embodiment of the present invention in which the float chamber 18 has in its lower portion an inlet 21 of the fuel bypass.
  • FIG. 3 shows a third embodiment of the present invention in which an outlet 26 of the fuel bypass is directly formed in the side surface of the venturi portion.
  • the venturi portion 6 is maintained at under constant negative pressure while the engine is driven.
  • the main fuel is metered by the metering needle 7 and the main jet 8 so as to keep constant air-fuel ratio with respect to the flow of air sucked in accordance with opening of the throttle valve 2 which corresponds to the engine load and is injected into the venturi portion.
  • the fuel to be injected into the fuel bypass 9 is directly sucked in the inlet 21 formed in the float chamber 18.
  • the air-fuel mixture in the fuel bypass 9 is directly injected from the outlet 26 of the fuel bypass formed in the venturi portion.
  • the fuel thus injected from the fuel bypass 9 into the venturi portion 6 is supplied in a constant flow regardless of the engine load.
  • the flow of the bypass fuel f is considerably smaller than the flow of the main fuel F flowing through the main jet 8 while the engine is driven under load.
  • the entire air-fuel ratio is substantially determined by the flow of the main fuel F and is almost constant while the engine is driven under load.
  • the ratio f/F of the flow of the bypass fuel f and the flow of the main fuel F becomes remarkably large in comparison with that in the case the engine is driven under load, and therefore the entire air-fuel ratio can be controlled by changing the flow of the fuel flowing through the fuel bypass 9.
  • the flow of the fuel flowing through the fuel bypass 9 can be easily controlled by regulating the adjust screw 10 and the variable air throttle 12.
  • the electromagnetic valve 19 is driven to substantially close the throttle 17 and decrease the flow of the fuel flowing through the outlet 16 and thereby the air flowing through the air throttles 12 and 13 is introduced into the upstream portion 14a of the main fuel passage 14 to quickly reduce the flow of the main fuel.
  • the engine is prevented from dieseling that might be caused by stoppage of the engine.

Landscapes

  • Engineering & Computer Science (AREA)
  • Chemical & Material Sciences (AREA)
  • Combustion & Propulsion (AREA)
  • Mechanical Engineering (AREA)
  • General Engineering & Computer Science (AREA)
  • Control Of The Air-Fuel Ratio Of Carburetors (AREA)
US06/219,524 1980-08-26 1980-12-23 Variable venturi carburetor Expired - Fee Related US4341723A (en)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
JP55-121546[U] 1980-08-26
JP1980121546U JPS6135720Y2 (it) 1980-08-26 1980-08-26

Publications (1)

Publication Number Publication Date
US4341723A true US4341723A (en) 1982-07-27

Family

ID=14813918

Family Applications (1)

Application Number Title Priority Date Filing Date
US06/219,524 Expired - Fee Related US4341723A (en) 1980-08-26 1980-12-23 Variable venturi carburetor

Country Status (6)

Country Link
US (1) US4341723A (it)
JP (1) JPS6135720Y2 (it)
DE (1) DE3128426A1 (it)
FR (1) FR2489421A1 (it)
GB (1) GB2082258B (it)
IT (1) IT1137827B (it)

Cited By (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4420439A (en) * 1981-02-10 1983-12-13 Bosch & Pierburg System Ohg Constant pressure carburettors
US4432911A (en) * 1981-06-10 1984-02-21 Aisan Kogyo Kabushiki Kaisha Variable venturi carburetor
US4508664A (en) * 1983-03-23 1985-04-02 Toyota Jidosha Kabushiki Kaisha Variable venturi-type carburetor
US4562012A (en) * 1981-12-24 1985-12-31 Toyota Jidosha Kabushiki Kaisha Variable venturi type carburetor
US5671045A (en) * 1993-10-22 1997-09-23 Masachusetts Institute Of Technology Microwave plasma monitoring system for the elemental composition analysis of high temperature process streams
US6081329A (en) * 1995-11-03 2000-06-27 Cohn; Daniel R. Compact trace element sensor which utilizes microwave generated plasma and which is portable by an individual

Families Citing this family (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS58144048U (ja) * 1982-03-23 1983-09-28 愛三工業株式会社 可変ベンチユリ気化器
JPS63166173A (ja) * 1986-12-26 1988-07-09 富士通株式会社 コネクタ装置
JPH0249379A (ja) * 1988-08-09 1990-02-19 Nec Corp 零挿入力コネクタ
CN102486138A (zh) * 2010-12-03 2012-06-06 上海坤孚企业(集团)有限公司 分控式智能化油器

Citations (12)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US1444222A (en) * 1914-09-10 1923-02-06 Packard Motor Car Co Carburetor
FR1290014A (fr) * 1961-05-26 1962-04-06 Prise de pression positive pour carburateurs et similaires
US3455260A (en) * 1965-10-25 1969-07-15 Sibe Carburettors for internal combustion engines
US3618581A (en) * 1968-09-05 1971-11-09 Zenith Carburateur Soc Du Carburetors for internal combustion engines
US3764120A (en) * 1970-10-09 1973-10-09 Honda Motor Co Ltd Air bleed adjusting device for the carburetor of an internal combustion engine
US3765658A (en) * 1970-10-24 1973-10-16 Deutsche Vergaser Gmbh Co Kg Carburetor for automotive vehicles
US3855974A (en) * 1972-04-22 1974-12-24 Bosch Gmbh Robert Apparatus to control the air-fuel mixture supplied to internal combustion engines
JPS5215932A (en) * 1975-07-28 1977-02-05 Yamaha Motor Co Ltd Carburetor
US4050436A (en) * 1976-03-17 1977-09-27 Crabtree Roger A Idle system blocking means
US4084562A (en) * 1972-08-08 1978-04-18 Robert Bosch Gmbh Fuel metering device
US4251472A (en) * 1978-07-19 1981-02-17 Pierburg Gmbh & Co. Kg Carburetor for combustion engines
US4276238A (en) * 1978-10-19 1981-06-30 Nissan Motor Company, Limited Carburetor with automatic choking and acceleration device

Family Cites Families (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
FR1466014A (fr) * 1966-01-27 1967-01-13 Honda Gijutsu Kenkyusho Kk Carburateur
FR2068019A5 (it) * 1969-11-25 1971-08-20 Zenith Carburetter Ltd
DE2238990A1 (de) * 1972-08-08 1974-02-14 Bosch Gmbh Robert Kraftstoffzumessanlage
JPS528883Y2 (it) * 1972-11-24 1977-02-24
FR2228158B1 (it) * 1973-05-04 1977-08-19 Sibe
BR7308306D0 (pt) * 1973-10-23 1975-06-03 S Louis Carburador a vacuo constante
JPS52135924A (en) * 1976-05-10 1977-11-14 Nissan Motor Co Ltd Air fuel ratio control equipment

Patent Citations (12)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US1444222A (en) * 1914-09-10 1923-02-06 Packard Motor Car Co Carburetor
FR1290014A (fr) * 1961-05-26 1962-04-06 Prise de pression positive pour carburateurs et similaires
US3455260A (en) * 1965-10-25 1969-07-15 Sibe Carburettors for internal combustion engines
US3618581A (en) * 1968-09-05 1971-11-09 Zenith Carburateur Soc Du Carburetors for internal combustion engines
US3764120A (en) * 1970-10-09 1973-10-09 Honda Motor Co Ltd Air bleed adjusting device for the carburetor of an internal combustion engine
US3765658A (en) * 1970-10-24 1973-10-16 Deutsche Vergaser Gmbh Co Kg Carburetor for automotive vehicles
US3855974A (en) * 1972-04-22 1974-12-24 Bosch Gmbh Robert Apparatus to control the air-fuel mixture supplied to internal combustion engines
US4084562A (en) * 1972-08-08 1978-04-18 Robert Bosch Gmbh Fuel metering device
JPS5215932A (en) * 1975-07-28 1977-02-05 Yamaha Motor Co Ltd Carburetor
US4050436A (en) * 1976-03-17 1977-09-27 Crabtree Roger A Idle system blocking means
US4251472A (en) * 1978-07-19 1981-02-17 Pierburg Gmbh & Co. Kg Carburetor for combustion engines
US4276238A (en) * 1978-10-19 1981-06-30 Nissan Motor Company, Limited Carburetor with automatic choking and acceleration device

Cited By (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4420439A (en) * 1981-02-10 1983-12-13 Bosch & Pierburg System Ohg Constant pressure carburettors
US4432911A (en) * 1981-06-10 1984-02-21 Aisan Kogyo Kabushiki Kaisha Variable venturi carburetor
US4562012A (en) * 1981-12-24 1985-12-31 Toyota Jidosha Kabushiki Kaisha Variable venturi type carburetor
US4508664A (en) * 1983-03-23 1985-04-02 Toyota Jidosha Kabushiki Kaisha Variable venturi-type carburetor
US5671045A (en) * 1993-10-22 1997-09-23 Masachusetts Institute Of Technology Microwave plasma monitoring system for the elemental composition analysis of high temperature process streams
US6081329A (en) * 1995-11-03 2000-06-27 Cohn; Daniel R. Compact trace element sensor which utilizes microwave generated plasma and which is portable by an individual

Also Published As

Publication number Publication date
FR2489421A1 (fr) 1982-03-05
JPS5743344U (it) 1982-03-09
DE3128426C2 (it) 1988-04-21
IT1137827B (it) 1986-09-10
DE3128426A1 (de) 1982-06-03
GB2082258A (en) 1982-03-03
GB2082258B (en) 1984-07-25
FR2489421B1 (it) 1984-11-09
IT8123415A0 (it) 1981-08-06
JPS6135720Y2 (it) 1986-10-17

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